Bacgrond: acute lymphoid leukemia (ALL) is the most common neoplasm in childhood. The probability of current overall survival is around 90% in developed countries. There are few studies that demonstrate the results in Brazil. This work aims to analyze the results of children with ALL treated at a single institution in Rio de Janeiro. Procedure: retrospective analysis survival study of a cohort of childhood ALL patients treated in Hemorio. Kaplan-Meier and log-rank methods were used for analysis of overall survival (OS) and events free survival (EFS) and the Cox proportional hazards regression model for multivariate analysis. Results: the probability of OS and EFS at 6 years was 52% and 45%. The probability of OS and EFS in 6 years for pacients aged 10-17 years was 31% and 28% and for the younger was 65% and 55% respectively (p<0.001). A probability of OS and EFS in 6 years for patients with more than 100.000 leukocytes/mm3 at diagnosis was 19% and 16% and those with less than 100.000 was 62% (p=0.007) and 55% (p= 0.008). Those who received less than 10 doses of native Echerichia coli asparaginase had a probability of OS and EFS in 6 years of 27% and 21% and that who received at least 10 doses was 74% and 65% (p<0.001). Conclusions: the presence of a high number of adolescents and high-risk patients, as well as many patients who discontinueted the use of asparaginase or any substitute led to a lower probability of OS and EFS in our cohort.